As depicted in FIG. 6, the prior art rifle weapon 20 has a lower receiver assembly 22. In the usual configuration of weapon 20, an upper receiver assembly 24 is mated to the lower receiver assembly 22.
The lower receiver assembly 22 of the weapon 20 has three major subcomponents: lower receiver 26, butt stock 28, and pistol grip 30. In assembly, the butt stock 28 is slid over the buffer tube 32 and secured to the lower receiver 26. Preferably, the buffer tube 32 has a buffer spring (not shown) and a buffer body assembly (not shown) disposed therein. The butt stock buffer spring and the buffer body assembly cooperate to minimize the recoil felt by the operator of the weapon 20 during discharge of ammunition therefrom when in the rifle mode of operation with the original upper receiver assembly 24 installed.
The pistol grip 30 is secured to the underside of the lower receiver 26 preferably by a screw (not shown) threaded into a threaded bore (not shown) disposed in the underside of the lower receiver 26.
A magazine receiver 34 is positioned in the forward portion of the lower receiver 26. The magazine receiver 34 has an aperture 36 defined therein. The aperture 36 is open at both the top and the bottom. The top opening 38 of the aperture 36 is designed to admit cartridges into the upper receiver assembly 24 for discharge therefrom.
The lower opening 40 of the aperture 36 is designed to receive a magazine inserted therein. The magazine (not shown) is held within the magazine receiver 34 by the magazine catch 42.
A trigger assembly 44, including a trigger 46, is positioned within the lower receiver 26 and held in position by pin 48. A hammer assembly 50 is also disposed within the lower receiver 26 and held in position by pin 52. The trigger assembly 44 and the hammer assembly 50 are disposed in a cooperative relationship such that when the hammer assembly 50 is in a cocked condition, actuation of the trigger 46 of the trigger assembly 44 acts to release the hammer assembly 50 to strike the primer of a cartridge, thereby discharging a cartridge loaded in the chamber 53 of the upper receiver assembly 24.
The upper receiver assembly 24 of the prior art weapon 20 typically includes two major subcomponents: upper receiver 60 and barrel assembly 62. The barrel assembly 62 has a barrel 64. The barrel 64 may have a compensator 66 at the muzzle end 68 thereof that is held in threaded engagement with the threads 70 of the barrel 64. A front sight 72 may be mounted on the forward portion of the barrel 64. A gas tube 74 may extend rearward from proximate the front sight 72 mounted on the barrel 64. The gas tube 74 supplies gas under pressure to the upper receiver 60 to assist in ejection of a spent cartridge (not shown) and the loading of a live cartridge (not shown) from the magazine. A pair of hand guards 76 are positioned around a portion of the barrel 64.
The rear portion of the barrel 64 has a barrel nut 78 designed to threadedly engage the barrel assembly 62 with the threads 79 of the upper receiver 60. A hand guard retainer 77 slides over the barrel nut 78 and fixes the hand guards 76 to the barrel 64.
The upper receiver 60 has an integral carrying handle 80. An aperture 82 defined in the side of the upper receiver 60 permits actuation of a bolt disposed within the upper receiver 60.
In the lower front portion of the upper receiver 60 is a downward directed forward locking lug 84. In the rear portion of the upper receiver 60 is a downward directed rear locking lug 86. The forward locking lug 84 and the rear locking lug 86 each have a single lug bore 88 defined therein. The lug bores carry through the respective locking lug 84, 86 from side to side. When the upper receiver assembly 24 is mated to the lower receiver assembly 22 of the weapon 20, the lug bore 88 of the forward locking lug 84 is positioned in registry with a receiver bore 90 defined in the side of the lower receiver 26. The lug bore 88 of the rear locking lug 86 is positioned in registry with the rear receiver bores 92. Locking pins 94 are then inserted through the receiver bore 90 and the lug bore 88 of the forward locking lug 84 and through the rear receiver bore 92 and the lug bore 88 of the rear locking lug 86 to removably secure the upper receiver assembly 24 to the lower receiver assembly 22 of the weapon 20. It should be understood that it is contemplated in the design of the weapon 20 that the locking pins 94 may be readily disengaged in order to permit the upper receiver assembly 24 to be detached from the lower receiver assembly 22.
Most weapons of the type described above are designed to discharge a primary type of ammunition. Typically such ammunition propels a relatively small caliber projectile at very high velocity. In order to balance the fire power of a force comprised of a number of individuals, there is a need to discharge alternate ammunition. Such ammunition may comprise a relatively large caliber grenade or flare, or a shotgun type shell. Also a chemical dispensing cartridge may be used such as a tear gas cartridge. Further, rifle and pistol cartridges of different size and caliber than the primary ammunition may be desired to be discharged.
In the past, an add on tube was designed to be mounted on an existing hand held weapon. Such add on tube is evidenced in the M203 grenade launcher adaptable to the M-16A1 rifle produced by J. C. Manufacturing, Inc. An alternative approach to providing the versatility in fire power was to design a weapon dedicated to discharging only the alternate type ammunition.
There are certain disadvantages attendant to the foregoing means for providing an alternative ammunition capability. With respect to the add on tube, the sight system on the hand held weapon that are set up for the ballistics of the primary ammunition are not readily adaptable to provide the user accurate information regarding the deployment of the alternative ammunition. Additionally, the add on tube adds complexity and weight to the existing hand held weapon. With respect to the weapon dedicated to the discharge of alternate ammunition, the member of the armed force carrying such dedicated weapon is denied the ability to use the primary ammunition when the situation calls for such use, unless an additional hand held weapon is carried by that member. Further, there is a need to have all the members of a force carry the same type of weapon. By arming some of such members with a weapon dedicated to the discharge of alternate ammunition, such commonality is not maintained.
Accordingly, the need to be able to discharge a variety of different types of ammunition remains. Such discharge should be affected with a single hand held weapon that is capable of being configured to discharge the primary ammunition as well as the alternate ammunition as desired. The breech block and barrel assembly of the receiver should be integrally formed to ensure that the receiver is capable of repeatably discharging in rapid succession the most intense ammunition available. Additionally, when configured to discharge alternate ammunition, a suitable sighting system for such ammunition should be provided. Such a device should minimize the complexity and weight added to an existing hand held weapon.